Signal generator with signal tracking

Abstract

Frequency and phase of an output signal is adjusted to track an input signal. A control signal is adjusted to control a frequency of an oscillating signal from which the output signal is derived. In some aspects the frequency of the oscillating signal is adjusted by reconfiguration of reactive circuits coupled to an oscillator circuit. Phase of the output signal may be adjusted based on comparison of the oscillating signal with an adjustable threshold. For example, the adjustable threshold may comprise an adjustable bias signal for a transistor circuit whereby the oscillating signal is provided as an input to the transistor circuit and the output of the transistor circuit provides the output signal.

1. An apparatus for providing an output signal that tracks an input signal, comprising:
 an oscillator circuit configured to provide an oscillating signal based on a control signal; 
 a comparator configured to compare the oscillating signal with an adjustable threshold to provide the output signal; and 
 a time and frequency tracking circuit configured to receive the output signal and the input signal, and further configured to cause a first frequency and a first phase of the output signal to respectively track a second frequency and a second phase of the input signal by:
 adjusting the control signal to control a third frequency of the oscillating signal; and 
 adjusting the adjustable threshold to control the first phase of the output signal. 
 
 
     
     
       2. The apparatus of  claim 1 , wherein:
 the oscillator circuit is further configured to provide the oscillating signal based on at least one other control signal; and 
 the time and frequency tracking circuit is further configured to adjust the at least one other control signal to control the third frequency of the oscillating signal based on the output and input signals. 
 
     
     
       3. The apparatus of  claim 1 , further comprising:
 at least one other comparator configured to compare the oscillating signal with at least one other adjustable threshold to provide at least one other output signal; 
 wherein the time and frequency tracking circuit is further configured to adjust the at least one other adjustable threshold to control a phase of each of the at least one other output signal. 
 
     
     
       4. The apparatus of  claim 3 , wherein the time and frequency tracking circuit is further configured to:
 receive the at least one other output signal and at least one other input signal; and 
 cause the at least one other output signal to track the at least one other input signal by adjusting the at least one other adjustable threshold. 
 
     
     
       5. The apparatus of  claim 3 , further comprising:
 a data memory configured to store a set of adjustable threshold values, each of which is associated with a different phase offset; 
 wherein the time and frequency tracking circuit is further configured to select at least one of the adjustable threshold values to adjust at least one phase of the at least one other output signal. 
 
     
     
       6. The apparatus of  claim 1 , wherein the oscillator circuit comprises a reactive circuit configured to provide, based on the control signal, a variable amount of capacitance, inductance, or capacitance and inductance for the oscillator circuit. 
     
     
       7. The apparatus of  claim 6 , wherein the reactive circuit comprises a switch configured to, in response to the control signal, couple and decouple a capacitive element, an inductive element, or capacitive and inductive elements to the oscillator circuit. 
     
     
       8. The apparatus of  claim 6 , wherein the reactive circuit comprises a variable capacitive element that provides the variable amount of capacitance based on the control signal, a variable inductive element that provides the variable amount of inductance based on the control signal, or variable capacitive and inductive elements that provide the variable amounts of capacitance and inductance based on the control signal. 
     
     
       9. The apparatus of  claim 1 , wherein the oscillator circuit comprises a crystal oscillator coupled in parallel with an inverter. 
     
     
       10. The apparatus of  claim 1 , wherein the time and frequency tracking circuit is further configured to repeatedly vary the control signal over a period of time to change an effective frequency of the oscillating signal over the period of time. 
     
     
       11. The apparatus of  claim 10 , wherein the time and frequency tracking circuit is further configured to define a duty cycle of the control signal to define the effective frequency. 
     
     
       12. The apparatus of  claim 1 , wherein:
 the comparator comprises an inverter having an adjustable decision threshold that determines a level of the oscillating signal that causes the inverter to switch polarity of the output signal; and 
 the adjustment of the adjustable threshold alters the decision threshold. 
 
     
     
       13. The apparatus of  claim 1 , wherein:
 the comparator comprises a transistor circuit having an adjustable bias; and 
 the adjustment of the adjustable threshold alters the bias. 
 
     
     
       14. The apparatus of  claim 1 , wherein the input signal comprises a clock signal that is recovered from a received signal. 
     
     
       15. The apparatus of  claim 1 , further comprising a data recovery circuit configured to recover data from ultra-wideband pulses based on the output signal. 
     
     
       16. The apparatus of  claim 15 , wherein the ultra-wideband pulses are associated with a fractional bandwidth on the order of 20% or more, a bandwidth on the order of 500 MHz or more, or a fractional bandwidth on the order of 20% or more and a bandwidth on the order of 500 MHz or more. 
     
     
       17. A method of providing an output signal that tracks an input signal, comprising:
 providing, by an apparatus, an oscillating signal based on a control signal; 
 comparing the oscillating signal with an adjustable threshold to provide the output signal; and 
 causing a first frequency and a first phase of the output signal to respectively track a second frequency and a second phase of the input signal by:
 adjusting the control signal to control a third frequency of the oscillating signal; and 
 adjusting the adjustable threshold to control the first phase of the output signal. 
 
 
     
     
       18. The method of  claim 17 , further comprising:
 providing the oscillating signal based on at least one other control signal; and 
 adjusting the at least one other control signal to control the third frequency of the oscillating signal based on the output and input signals. 
 
     
     
       19. The method of  claim 17 , further comprising:
 comparing the oscillating signal with at least one other adjustable threshold to provide at least one other output signal; and 
 adjusting the at least one other adjustable threshold to control a phase of each of the at least one other output signal. 
 
     
     
       20. The method of  claim 19 , further comprising causing the at least one other output signal to track at least one other input signal by adjusting the at least one other adjustable threshold. 
     
     
       21. The method of  claim 19 , further comprising:
 storing a set of adjustable threshold values, each of which is associated with a different phase offset; 
 selecting at least one of the adjustable threshold values to adjust at least one phase of the at least one other output signal. 
 
     
     
       22. The method of  claim 17 , further comprising providing, based on the control signal, a variable amount of capacitance, a variable amount of inductance, or variable amounts of capacitance and inductance for an oscillator circuit that provides the oscillating signal. 
     
     
       23. The method of  claim 22 , further comprising, in response to the control signal, coupling and decoupling a capacitive element, an inductive element, or capacitive and inductive elements to the oscillator circuit. 
     
     
       24. The method of  claim 22 , further comprising:
 adjusting capacitance of a variable capacitive element based on the control signal; 
 adjusting inductance of a variable inductive element based on the control signal; or 
 adjusting capacitance and inductance of variable capacitive and inductive elements based on the control signal. 
 
     
     
       25. The method of  claim 17 , wherein an oscillator circuit that provides the oscillating signal comprises a crystal oscillator coupled in parallel with an inverter. 
     
     
       26. The method of  claim 17 , further comprising repeatedly varying the control signal over a period of time to change an effective frequency of the oscillating signal over the period of time. 
     
     
       27. The method of  claim 26 , further comprising defining a duty cycle of the control signal to define the effective frequency. 
     
     
       28. The method of  claim 17 , wherein:
 the comparison is performed by an inverter having an adjustable decision threshold that determines a level of the oscillating signal that causes the inverter to switch polarity of the output signal; and 
 the adjustment of the adjustable threshold alters the decision threshold. 
 
     
     
       29. The method of  claim 17 , wherein:
 the comparison is performed by a transistor circuit having an adjustable bias; and 
 the adjustment of the adjustable threshold alters the bias. 
 
     
     
       30. The method of  claim 17 , wherein the input signal comprises a clock signal that is recovered from a received signal. 
     
     
       31. The method of  claim 17 , further comprising recovering data from ultra-wideband pulses based on the output signal. 
     
     
       32. The method of  claim 31 , wherein the ultra-wideband pulses are associated with a fractional bandwidth on the order of 20% or more, a bandwidth on the order of 500 MHz or more, or a fractional bandwidth on the order of 20% or more and a bandwidth on the order of 500 MHz or more. 
     
     
       33. An apparatus for providing an output signal that tracks an input signal, comprising:
 means for providing an oscillating signal based on a control signal; 
 means for comparing the oscillating signal with an adjustable threshold to provide the output signal; and 
 means for causing a first frequency and a first phase of the output signal to respectively track a second frequency and a second phase of the input signal by:
 adjusting the control signal to control a third frequency of the oscillating signal; and 
 adjusting the adjustable threshold to control the first phase of the output signal. 
 
 
     
     
       34. The apparatus of  claim 33 , wherein:
 the means for providing further provides the oscillating signal based on at least one other control signal; and 
 the means for causing adjusts the at least one other control signal to control the third frequency of the oscillating signal based on the output and input signals. 
 
     
     
       35. The apparatus of  claim 33 , wherein:
 the means for comparing compares the oscillating signal with at least one other adjustable threshold to provide at least one other output signal; and 
 the means for causing adjusts the at least one other adjustable threshold to control a phase of each of the at least one other output signal. 
 
     
     
       36. The apparatus of  claim 35 , wherein the means for causing:
 receives the at least one other output signal and at least one other input signal; and 
 causes the at least one other output signal to track the at least one other input signal by adjusting the at least one other adjustable threshold. 
 
     
     
       37. The apparatus of  claim 35 , further comprising:
 means for storing a set of adjustable threshold values, each of which is associated with a different phase offset; 
 wherein the means for causing selects at least one of the adjustable threshold values to adjust at least one phase of the at least one other output signal. 
 
     
     
       38. The apparatus of  claim 33 , wherein the means for providing provides, based on the control signal, a variable amount of capacitance, inductance, or capacitance and inductance for the means for providing. 
     
     
       39. The apparatus of  claim 38 , wherein the means for providing, in response to the control signal, couples and decouples a capacitive element, an inductive element, or capacitive and inductive elements to the means for providing. 
     
     
       40. The apparatus of  claim 38 , wherein the means for providing comprises:
 a variable capacitive element for providing the variable amount of capacitance based on the control signal; 
 a variable inductive element for providing the variable amount of inductance based on the control signal; or 
 variable capacitive and inductive elements for providing the variable amounts of capacitance and inductance based on the control signal. 
 
     
     
       41. The apparatus of  claim 33 , wherein the means for providing comprises a crystal oscillator coupled in parallel with an inverter. 
     
     
       42. The apparatus of  claim 33 , wherein the means for causing repeatedly varies the control signal over a period of time to change an effective frequency of the oscillating signal over the period of time. 
     
     
       43. The apparatus of  claim 42 , wherein the means for causing defines a duty cycle of the control signal to define the effective frequency. 
     
     
       44. The apparatus of  claim 33 , wherein:
 the means for comparing comprises an inverter having an adjustable decision threshold that determines a level of the oscillating signal that causes the inverter to switch polarity of the output signal; and 
 the adjustment of the adjustable threshold alters the decision threshold. 
 
     
     
       45. The apparatus of  claim 33 , wherein:
 the means for comparing comprises a transistor circuit having an adjustable bias; and 
 the adjustment of the adjustable threshold alters the bias. 
 
     
     
       46. The apparatus of  claim 33 , wherein the input signal comprises a clock signal that is recovered from a received signal. 
     
     
       47. The apparatus of  claim 33 , further comprising means for recovering data from ultra-wideband pulses based on the output signal. 
     
     
       48. The apparatus of  claim 47 , wherein the ultra-wideband pulses are associated with a fractional bandwidth on the order of 20% or more, a bandwidth on the order of 500 MHz or more, or a fractional bandwidth on the order of 20% or more and a bandwidth on the order of 500 MHz or more. 
     
     
       49. A computer-program product for providing an output signal that tracks an input signal, comprising:
 a non-transitory computer-readable medium comprising codes executable by at least one computer to:
 provide an oscillating signal based on a control signal; 
 compare the oscillating signal with an adjustable threshold to provide the output signal; and 
 cause a first frequency and a first phase of the output signal to respectively track a second frequency and a second phase of the input signal by adjusting the control signal to control a third frequency of the oscillating signal and by adjusting the adjustable threshold to control the first phase of the output signal. 
 
 
     
     
       50. A headset, comprising:
 an oscillator circuit configured to provide an oscillating signal based on a control signal; 
 a comparator configured to compare the oscillating signal with an adjustable threshold to provide an output signal; 
 a time and frequency tracking circuit configured to receive the output signal and an input signal, and further configured to cause a first frequency and a first phase of the output signal to respectively track a second frequency and a second phase of the input signal by adjusting the control signal to control a third frequency of the oscillating signal and by adjusting the adjustable threshold to control the first phase of the output signal; and 
 a transducer adapted to provide an audio output based on data that is provided through the use of the oscillating signal. 
 
     
     
       51. A watch, comprising:
 an oscillator circuit configured to provide an oscillating signal based on a control signal; 
 a comparator configured to compare the oscillating signal with an adjustable threshold to provide an output signal; 
 a time and frequency tracking circuit configured to receive the output signal and an input signal, and further configured to cause a first frequency and a first phase of the output signal to respectively track a second frequency and a second phase of the input signal by adjusting the control signal to control a third frequency of the oscillating signal and by adjusting the adjustable threshold to control the first phase of the output signal; and 
 a user interface adapted to provide an indication based on data that is provided through the use of the oscillating signal. 
 
     
     
       52. A sensing device for wireless communication, comprising:
 an oscillator circuit configured to provide an oscillating signal based on a control signal; 
 a comparator configured to compare the oscillating signal with an adjustable threshold to provide an output signal; 
 a time and frequency tracking circuit configured to receive the output signal and an input signal, and further configured to cause a first frequency and a first phase of the output signal to respectively track a second frequency and a second phase of the input signal by adjusting the control signal to control a third frequency of the oscillating signal and by adjusting the adjustable threshold to control the first phase of the output signal; and 
 a sensor adapted to provide data to be transmitted through the use of the oscillating signal.